WEBRTC (web real-time communication) is the technology supporting a web browser to perform real-time audio conversations or video conversions, where a browser capable of performing WEBRTC communications is referred to as a WEBRTC terminal. The browsers performing real-time communications must support an SRTP (secure real-time transport protocol) to encrypt media resources, and support an ICE (interactive connectivity establishment) function to traverse an NAT (network address translation) device and firewalls.
An IMS (IP multimedia subsystem) is a network system architecture providing voice services, i.e. multimedia services, based on an IP network, which uses an SIP (session initiation protocol) to perform end-to-end call control, where a device or a soft terminal in conformity with an SIP standard protocol is referred to as an SIP terminal. Most of SIP terminals neither support the ICE function nor the SRTP.
In the prior art, a process of establishing a media channel between a WEBRTC terminal and a called terminal based on an IMS network by the WEBRTC terminal is: after registering in the IMS network successfully, the WEBRTC terminal transmits a session request message to a WEBRTC signaling gateway device, where the WEBRTC signaling gateway device applies for a media endpoint from a WEBRTC media gateway device after receiving the session request message, and the media endpoint converts a format of media data and terminates an ICE process, the WEBRTC signaling gateway device modifies an SDP (session description protocol) in the session request message, modifies an SRTP described by the SDP into an RTP, and deletes the ICE, then the WEBRTC signaling gateway device transmits the modified session request message to an IMS signaling gateway device, the IMS signaling gateway device transmits the modified session request message to the called terminal via the IMS network after applying for a media endpoint from an IMS media gateway device, the called terminal replies a session response message to the WEBRTC terminal, where both the session request message and the session response message include media candidate address information of media gateway device so as to enable the WEBRTC terminal and the called terminal to respectively establish a media channel between the WEBRTC/called terminal and a corresponding media gateway device according to the media candidate address information of the media gateway device. The media candidate address information of the media gateway device includes media candidate address information of the WEBRTC media gateway device or media candidate address information of the IMS media gateway device, then during data transmission, the WEBRTC media gateway device and the IMS media gateway device need to complete conversion of data formats, and the WEBRTC media gateway device also needs to terminate the ICE process.
It can be seen from the above descriptions that, when the called terminal is the SIP terminal, the above process may achieve good application effects, however, when the called terminal is the WEBRTC terminal, the above described data transmission process increases the data transmission path length, and increases network delays and load of the media gateway devices.